My G26L which has not had one failure is running a G17 Spring thats trimmed a little and a G19 locking block that I ground the ear tips down a touch. Use a G26 lower parts kit, G19 complete slide, and ...

PLA (Optionally Nylon [645 is tested good], PETG). I reccomend PLA, as it is cheap, easy to print, and is what I designed the mag in. A printer capable of printing PLA (or the plastic you choose to ...